Method to Reduce Blanking Area for Palm Rejection in Low Cost In-Cell Displays

1. A method in a device that has a touch screen, the method comprising: receiving first touch intensity signals from a two-dimensional (2D) spatial array of touch sensors of the touch screen, a spatial pattern of magnitudes of the first touch intensity signals corresponding to at least a three-dimensional (3D) deformation contour in the touch screen; detecting, based on a comparison of the magnitudes of the first touch intensity signals to a first touch-detection threshold, a touched region of the touch screen; and in response to determining that the touched region of the touch screen corresponds to an unintended touched region: assigning a second touch-detection threshold to a first perimeter region surrounding the unintended touched region of the touch screen, wherein the second touch-detection threshold corresponds to a greater magnitude touch intensity signal than a magnitude of touch intensity signal corresponding to the first touch detection threshold, and wherein second touch intensity signals received in the first perimeter region are detectable based on the second touch-detection threshold and the first perimeter region surrounding the unintended touched region corresponds to a reduced touch sensitivity relative to the unintended touched region of the touch screen.

2. The method of claim 1 , wherein the spatial pattern of magnitudes of the first touch intensity signals corresponding to the 3D deformation contour in the touch screen is determined based on analysis of at least a slope of the touch intensity signals.

3. The method of claim 1 , wherein the unintended touched region corresponds to a detected palm touch.

4. The method of claim 1 , wherein the second touch-detection threshold is a constant value.

5. The method of claim 1 , wherein the second touch-detection threshold is variable over the first perimeter region of the touch screen.

6. The method of claim 1 , wherein the second touch-detection threshold varies in the first perimeter region proportionally with a slope of the first touch intensity signals from the first perimeter region of the touch screen.

7. The method of claim 1 , further comprising: dynamically adjusting the first touch-detection threshold by an offset determined based on a slope of the first touch intensity signals from the first perimeter region of the touch screen to arrive at the second touch-detection threshold.

8. The method of claim 1 , further comprising: designating a second perimeter region between the unintended touched region of the touch screen and the first perimeter region as a touch rejection region.

9. The method of claim 1 , further comprising: assigning the first touch-detection threshold to a region ranging from the first perimeter region to a perimeter of the touch screen.

10. A system in a device that has a touch screen, the system comprising: one or more processors; and one or more memory devices that store program code of a first computer program to be executed by the one or more processors, the program code configured to: receive first touch intensity signals from a two-dimensional (2D) spatial array of touch sensors of the touch screen, magnitudes of the first touch intensity signals corresponding to at least a three-dimensional (3D) deformation contour in the touch screen; detect, based on a comparison of the magnitudes of the first touch intensity signals to a first touch-detection threshold, a touched region of the touch screen; determine that the touched region of the touch screen corresponds to an unintended touched region; and in response to the touched region corresponding to the unintended touched region, assign a second touch-detection threshold to a first perimeter region surrounding the unintended touched region of the touch screen, wherein the second touch-detection threshold corresponds to a greater magnitude touch intensity signal than a magnitude of touch intensity signal corresponding to the first touch detection threshold, and wherein second touch intensity signals received in the first perimeter region are detectable based on the second touch-detection threshold and the first perimeter region surrounding the unintended touched region corresponds to a reduced touch sensitivity relative to the unintended touched region of the touch screen.

11. The system of claim 10 , wherein the program code is further configured to determine that the spatial pattern of magnitudes of the first touch intensity signals corresponds to the 3D deformation contour in the touch screen based on analysis of at least a slope of the first touch intensity signals.

12. The system of claim 10 , wherein the unintended touched region corresponds to a detected palm touch.

13. The system of claim 10 , wherein the second touch-detection threshold is a constant value.

14. The system of claim 10 , wherein the second touch-detection threshold is variable over the first perimeter region of the touch screen.

15. The system of claim 10 , wherein the second touch-detection threshold varies in the first perimeter region proportionally with a slope of the first touch intensity signals from the first perimeter region of the touch screen.

16. The system of claim 10 , wherein the program code is further configured to: dynamically adjust the first touch-detection threshold by an offset determined based on a slope of the first touch intensity signals from the first perimeter region of the touch screen to arrive at the second touch-detection threshold.

17. The system of claim 10 , wherein the program code is further configured to: designate a second perimeter region between the unintended touched region of the touch screen and the first perimeter region as a touch rejection region.

18. The system of claim 10 , wherein the program code is further configured to: assign the first touch-detection threshold to a region ranging from first perimeter region to a perimeter of the touch screen.

19. A computer-readable hardware device having program code recorded thereon that when executed by at least one processor causes the at least one processor to perform a method, the method comprising: receiving first touch intensity signals from a two-dimensional (2D) spatial array of touch sensors of a touch screen, magnitudes of the first touch intensity signals corresponding to at least a three-dimensional (3D) deformation contour in the touch screen; detecting, based on a comparison of the magnitudes of the first touch intensity signals to a first touch-detection threshold, a touched region of the touch screen; and in response to determining that the touched region of the touch screen corresponds to an unintended touched region: assigning a second touch-detection threshold to a first perimeter region surrounding the unintended touched region of the touch screen, wherein the second touch-detection threshold corresponds to a greater magnitude touch intensity signal than a magnitude of touch intensity signal corresponding to the first touch detection threshold, and wherein second touch intensity signals received in the first perimeter region are detectable based on the second touch-detection threshold and the first perimeter region surrounding the unintended touched region corresponds to a reduced touch sensitivity relative to the unintended touched region of the touch screen.

20. The computer readable hardware device of claim 19 , wherein the method further comprises dynamically adjusting the first touch-detection threshold by an offset determined based on a slope of the first touch intensity signals from the first perimeter region of the touch screen to arrive at the second touch-detection threshold.